Shuttle thread control



1967 M. R. LIVINGSTON ETAL 3,303,858

SHUTTLE THREAD CONTROL I Filed Sept. 4, 1964 2 Sheets-Sheet l M. R. LIVINGSTON ETAL 3,303,858

SHUTTLE THREAD CONTROL Feb. 14, we?

2 Sheets-Sheet 2 Filed Sept. 4, 1.964

United States atetit Patented Feb. 14, 1967 3,303,858 SHUTTLE THREAD CONTROL Malcolm R. Livingston, Charlotte, N.C., Hugh A. Haynie, Ripplemead, Va., Francis R. Lowder, Lowell, N.C., and Alfred L. Cate, Somerset, N.J., assignors to Celanese Corporation of America, New York, N.Y., a corporation of Delaware Filed Sept. 4, 1964, Ser. No. 394,535 5 Claims. (Cl. 139212) This invention relates to the art of weaving, more particularly to an improvement in the weaving of fabrics composed of warp and weft yarns so as to eliminate defects such as shiers and cracks which occur generally in low count filament acetate fabrics.

Notwithstanding the use of relatively uniform quality yarn, in the weaving of textile fabrics from these yarns, problems are often encountered in obtaining desired uniformity of quality of the woven fabric. These defects such as cracks and shiers reduce the quality of the Woven fabric, and in the case of fabrics woven of low count acetate filament yarns prevent economical fabric production, mitigating against the use of scch low count yarns. These defects occur primarily in the weft of the fabric.

It is accordingly among the primary objects of this invention to provide improved means for eliminating weftwise defects in woven fabrics.

A further object of the invention is to provide improved means for modifying a shuttle so as to obtain desired control over the weft threads during Weaving to effect desired quality control.

It is also an object of the invention to provide an improved method for weaving fabrics, particularly low count filament acetate fabrics.

A further object of the invention is to provide an improved shuttle implementing desired weft yarn control during weaving.

These and other objects of the invention which will become hereafter apparent are achieved by equalizing yarn tension in both directions of shuttle movement across the loom. This is most readily accomplished by providing auxiliary yarn tensioning means to act on the yarn fed from the shuttle as the shuttle moves from the battery to the lever side of the loom. Said tensioning means are auxiliary to the conventionally provided yarn tensioning means which apply yarn tension in both directions of shuttle movement, but which do not equalize the tension differential caused by the fact that the yarn drags along the full length of the side of the shuttle only when the shuttle moves from the lever side to the battery side of the 100m and not when the shuttle moves from the battery side to the lever side.

An important feature of the invention resides in the ability to lay picks evenly in place in the warp shed, and to maintain said picks in the warp shed under some degree of tension until beat up occurs.

Another feature of the invention resides in the ability to maintain a uniformity of spacing between alternating picks, so as to permit the weaving of uniform quality fabric.

The specific details of the invention, the method of practicing same, and a proposed shuttle modified in accord ance with the teachings of this invention will be made most manifest and particularly pointed out in clear, concise, and exact terms in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a shuttle modified in accordance with the teachings of this invention:

FIG. 2 is an exploded detail view of the auxiliary pressure plates applied to the conventional shuttle to provide tension control of the weft yarns laid down by the shuttle as it moves from the battery to the lever side of the loom;

FIGURE 3 is a schematic view showing the weft yarn engaged in the tension means according to the invention when the shuttle is moving away from the battery side of the loom toward the lever side;

FIGURE 4 is a schematic view showing the weft yarn being engaged by the shuttle substantially along its length when the shuttle is moving from the lever side to the battery side of the loom but not being engaged in the auxiliary tension means; and

FIGURE 5 is a partial side elevation of a shuttle showing an alternative embodiment of an auxiliary tension means according to the invention.

Referring now more particularly to the drawings, like numerals in the various figures will be employed to designate like parts.

Slow motion studies made by high speed motion pictures of a loom in operation indicate a major difference in behavior of picks laid down in the warp shed as the shuttle goes from the battery to the lever side, as opposed to those laid down as the shuttle travels in the reverse direction. When the shuttle is moving from battery to the lever side, the picks whip around, and oscillate within the shed, moving into the hinge of the warp shed and back out again. On the other hand, picks inserted as the shuttle moves from the lever to the battery side of the loom appear in these motion pictures to be laid evenly in place, moving evenly into the hinge of the warp shed, and re maining there under some degree of tension until beat up occurs. Whatever cracks are formed, occur almost invariably at beat up of the loose, freely shifting picks, inserted as the shuttle moves from the battery to the lever side.

Pickspacing studies indicate that there is probably a very consistent alternation in width of pickspacing in practically all of the low count fabrics. In higher quality fabrics, such as those graded one or perfect, little, if any, spacing variations appear throughout the area of the fabric.

However, alternating picks present a compact, open, compact, open, etc. appearance, indicating a difference in tension between alternating picks during beat up. These differences in tension on the filling yarn as it is delivered in different directions of shuttle travel across the loom are of course known, since normal designations of shuttle tension employ two values, e.g., 10 15, serving to indicate permissible differences in delivery tension.

According to this invention, it is found that the undesired shiers, cracks, and the like defects may be eliminated by controlling the tension of the weft yarn so that it is substantially the same in both directions of travel of the shuttle so as to eliminate the oscillation of the weft yarn in the warp shed during movement of the shuttle from the battery to the lever side of the loom.

It has been empirically determined that Where the tension on the yarn is maintained equal in both directions of movement of the shuttle through the warp shed, undesired defects in weaving may be substantially elimi nated. Thus on a loom having /RSMZ/40 acetate warp and 150/RSMZ/4O bright acetate filling having a lubricant thereon which tends to produce cracks in fabric,

at room conditions at 83 F. and 60% relative humidity,

a quill of the filling yarn woven in a normal shuttle with shuttle tension adjusted to 15x10, four static cracks were counted. By thereafter arranging this quill in a shuttle provided with an additional tensioning device permitting additional yarn tension in the battery to lever side direction of shuttle flight, with the tensions adjusted to 15 X15, only one static crack was observed. Utilizing the same yarns, under the same temperature and humidity conditions, but increasing tension to 27x27, no cracks were observed.

In a suggested arrangement, as illustrated in FIG. 1, the shuttle 10 is formed with a conventional pirn engaging clip assembly 12 adapted to engage the head 14 of the pirn or quill 15 of weft yarn. The lever end of the shuttle is provided with a cap 16, while the battery end of the shuttle is provided with a nose cone 17 in conventional fashion.

At the battery end of the shuttle, as seen to the left in the drawing, a conventional tensioning device 20 is secured comprising, in the illustrated embodiment of the invention, two pressure plates 21 and 22 which are preferably spring pressed towards each other. The thread T coming from the pirn 15 passes between these pressure plates 21 and 22, then over internal guide pin 24, and past exit guide pin 25. Internal guide pin 24 is conventionally made up of steel providing little frictional resistance to the passage of yarn T over the surface thereof, and exit guide pin 25 is preferably made up of polytetrafiuoroethylene or the like material having a low coefl'icient of friction with respect to conventional textile yarns. It will be understood by those skilled in the art that since the pressure exerted between the pressure plates 21 and 22 may be controlled, while the coefficient of friction between the guide pins 24 and 25 and the yarn is not subject to control, it is preferred to fabricate the guide pins of a material which is generally of a relatively low coefficient of friction with respect to that of the yarn, retaining control only between the pressure plates 21 and 22. Additional guide pins (not here illustrated) may be arranged between internal pin 24 and exit pin 25 to effect yarn guiding as desired.

In the illustrated embodiment of the inventon, a second tensioning device 26, here shown as comprising a pair of tension plates 27 and 28, are arranged in the exit slot of the shuttle. Pressure plates 27 and 28 may be formed in any conventional form. However, in the illustrated embodiment of the invention they are shown as formed with a fixed plate 27 apertured at one end and arranged slidably over pin 29. Plate 28 is similarly apertured and slidably mounted on pin 29, and a spring 30 biases plate 28 against plate 27. It will be understood by those skilled in the art that the thread in passing between pressure plates 27 and 28 comes up against pin 29.

Adjusting screws 31 extend against spring 30 to permit variation in pressure between the pressure plates 27 and 28.

It is contemplated within the scope of the invention that other types of tensioning means may be employed on the shuttle in lieu of tensioning means 26. Thus pins 25 and 29 may be replaced by pins 32, 33, respectively, as shown in FIGURE 5 of the drawing having differing surface characteristics. In order to equalize the tension on the yarn fed from the shuttle 10 in both directions of travel of the shuttle, pin 33 is formed with a smooth, glossy surface which produces more tension in yarns running over it, while the pin 32 will be formed with a satin or matte finish i.e., a dull, or evenly rough surface, which produces lower tensions. Thus the combined action of the pins along with the conventional pressure plates will result in an equalization of tension in both directions of shuttle travel.

Another possibility contemplated within the scope of this invention is the utilization of magnets embedded in the shuttle raceway to apply an attractive force (or repulsion) to the tension plates depending on the position of the shuttle in the loom raceway. Thus when greater tension is desired, the magnets will be arranged in the raceway to bring the tension plates closer together, while when lesser tension is desired the magnets are positioned in the raceway to separate the tension plates. Such magnets might apply load to the plates, and thereby tension to the yarn, only very near the ends of the shuttle traverse to hold delivered yarn taut in the warp shed until it is heat into the cloth. Other possibilities include varying tensions by use of magnets of varying strength along the raceway permitting differing weaving effects to be obtained.

Still another possibility contemplated within the scope of this invention is the utilization of any of the above described auxiliary tensioning means for the purpose of increasing, rather than eliminating, the difference between the yarn tensions in the two directions of shuttle movement thereby to obtain fabric with a distinct pick-andpick pattern; viz., alternate picks, the ones which are laid in during the lower tension direction of shuttle movement are crinkled while the other picks are uncrinkled or less crinkled. The above described conventional tension differential, while sufficient to cause the above described fabric defects, is not sufiicient to create such a distinct pick-and-pick pattern.

Operation In conventional weaving operations (not shown in the drawing) well known to those skilled in the art of weaving and as described, e.g., in United States 2,777,474 issued January 15, 1957, at pages l59213 in Textile Engineering Processes (1959) by A. H. Nissan, and at pages 269- 280 in Introduction to Textiles (1960) by E. E. Stout, a plurality of parallel warp yarns proceed from a loom beam to heddles and thence through dents of a reed. The heddles manipulate the warp yarns to separate them into two layers thus forming an opening called a shed. A shuttle mounted on a raceway proceeds from the battery side of the loom to the lever side inserting a pick of weft yarn through the warp shed. The heddles are again manipulated to close the warp shed and to form a second shed. At substantially the same time as the shed in the warp is closed, the reed beats up the weft. As the reed moves from the fell of the cloth, the shuttle is propelled from the lever side of the loom along the raceway and through the second open warp shed inserting another pick of weft yarn. The heddles are again manipulated to close the second warp shed and to form a third shed; and the reed heats up the second weft pick as described above. The steps are repeated to produce a woven cloth of the desired length.

In use the improved shuttle according to our inventive concept serves to eliminate weaving defects such as shiers, breaks or the like which interfere with the desired quality of production particularly in the case of low count filament acetate fabrics.

According to the invention, it has been empirically determined that with .such low count filament fabrics. If yarn tension is maintained equal in both directions of shuttle travel through the warp shed, as the weft pick is laid in the shed, breaks are substantially eliminated. The significant feature of this process is the elimination of differing tensions on filling yarns as they are inserted in the fabric from the battery to lever side and vice versa. This tension control may be illustratively achieved by utilizing a modified shuttle provided with a tensioning element serving to apply desired tension to the yarn as it is fed from the shuttle during movement of the shuttle from the battery to the lever side.

The invention is most readily practiced by modifying the conventional shuttle to provide a secondary tensioning device, auxiliary to the conventionally employed tension devices on the shuttle. This secondary tensioning device acts on the yarn only during movement of the shuttle from the battery to the lever side, and is adjusted to insure the same tension in the yarn in both directions of .shuttle movement across the loom.

In the illustrated embodiment of the invention, the shuttle 10 as shown in the figures of the drawing is provided with an auxiliary tensioning device 26 in the form of tensioning plates 27 and 28. The yarn T is shown in FIGURE 3 being fed from the shuttle 10 as the shuttle moves through the warp shed (not shown for sake of clarity) away from selved-ge S in the direction indicated by the arrow from the battery to the lever side of the loom, in which case the yarn is engaged in tension device Upon movement of the shuttle in the opposite direction from the lever to the battery side, i.e., away from selvedge S as indicated by the arrow in FIGURE 4, it will be understood by those skilled in the art that the yarn T (as shOWn in dotted line in FIGURE 1) is not engaged by tensioning deivce 26, and is subject only to the control of tensioning plates 21 and 22. In accordance with an alternative embodiment of the invention, as described above, and as more clearly shown by a comparison of FIGURES 4, 5, pin 25' and tensioning means 26 in the shuttle shown in FIGURE 4 are replaced by pins 32, 33, respectively, having difierent surface and therefore different frictional characteristics. As is deemed obvious from the shuttle movement indicated by the arr-ow in FIGURE 5, yarn T in engaged with and moves across pin 33 only when the shuttle is moving from the battery to the lever side of the loom. Because pin 33 is provided with a smooth finish in contrast to the matte finish of pin 32, the combined action of the pins along with the conventional pressure plates 21, 22 will result in equalization of tension on the yarn in both directions of shuttle travel.

It is thus seen that an improved means of weaving particularly applicable in the weaving of low count filament fabrics has been provided serving to eliminate the occurrence of undesirable shiers, breaks, or the like defects.

It is to be understood that the foregoing detailed description is given merely by way of illustration, and that many variations maybe made therein without departing from the spirit of our invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Shuttle having a battery end and a lever end corresponding to the battery side and lever side of a loom comprising means for retaining a pirn of weft yarn, means guiding said weft yarn from said pirn to the exterior of the shuttle, a first tension means for engaging said yarn as it is guided between said pirn and said shuttle exterior, said first tensioning means comprising a pair of pressure plates and being en-gageable with said yarn during both directions of movement of the shuttle in the loom, a second tensioning means for engaging said yarn, said second tensioning means being located between said first tesioning means and said shuttle exterior and comprising a pair of pressure plates adjustably mounted face-to-face and between which said yarn is engagea-ble only during the movement of the shuttle from the battery side to the lever side of the loom to thereby provide equal tension on the yarn in both directions of travel of the shuttle.

2. In a loom shuttle comprising a battery end and a lever end, means for mounting in said shuttle a pirn of yarn, an exit slot for said yarn at said battery end, and first tensioning means mounted at said battery end in the path of said yarn between said pirn and said slot, said first tensioning means being engageable with said yarn during both directions of movement of the shuttle in a loom, the improvement which comprises second tensioning means mounted in said slot, said second tensioning means being engageable with said yarn only during the movement of the shuttle from battery side to lever side of the loom.

3. The improvement of. claim 2, wherein said second tensioning means comprises a pair of pressure plates adjustably mounted face-to-face and between which said yarn is engageable.

4. In a loom shuttle comprising a battery end and a lever end, means for mounting in said shuttle a pirn of yarn, an exit slot for said yarn at said battery end, and first tensioning means mounted at said battery end in the path of said yarn between said pirn and said slot, said first tensioning means being engageable with said yarn during both directions of movement of the shuttle in a loom, the improvement which comprises second tensioning means mounted in said slot, said second tensioning means comprising a first guide pin and a second guide pin, said first guide pin being engage-able with said yarn when said shuttle moves from lever side to battery side of the loom and said second guide pin being engageable with said yarn when said shuttle moves from battery side to lever side of the loom, said first guide pin having a different surface from said second guide pin and therefore producing less tension on the yarn engaged with it than the second guide pin.

5. The improvement of claim 4, wherein said first guide pin has a matte surface and said second guide pin has a smooth, glossy surface.

References Cited by the Examiner UNITED STATES PATENTS 748,887 1/1904 Sawyer 139200 1,905,266 4/1933 Caldwell 139-212 2,281,204 4/1942 Raymond 139212 2,288,468 6/1942 Lilley et al 139-199 2,319,864 5/1943 Holmes 139200 2,923,327 2/1960 Ritsky 139-201 M'ERVIN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

H. S. JAUDON, Assistant Examiner. 

1. SHUTTLE HAVING A BATTERY END AND A LEVER END CORRESPONDING TO A BATTERY SIDE AND LEVER SIDE OF A LOOM COMPRISING MEANS FOR RETAINING A PIRN OF WEFT YARN, MEANS GUIDING SAID WEFT YARN FROM SAID PIRN TO THE EXTERIOR OF THE SHUTTLE, A FIRST TENSION MEANS FOR ENGAGING SAID YARN AS IT IS GUIDED BETWEEN SAID PIRN AND SAID SHUTTLE EXTERIOR, SAID FIRST TENSIONING MEANS COMPRISING A PAIR OF PRESSURE PLATES AND BEING ENGAGEABLE WITH SAID YARN DURING BOTH DIRECTIONS OF MOVEMENT OF THE SHUTTLE IN THE LOOM, A SECOND TENSIONING MEANS FOR ENGAGING SAID YARN, SAID SECOND TENSIONING MEANS BEING LOCATED BETWEEN SAID FIRST TENSIONING MEANS AND SAID SHUTTLE EXTERIOR AND COMPRISING A PAIR OF PRESSURE PLATES ADJUSTABLY MOUNTED FACE-TO-FACE AND BETWEEN WHICH SAID YARN IS ENGAGEABLE ONLY DURING THE MOVEMENT OF THE SHUTTLE FROM THE BATTERY SIDE TO THE LEVER SIDE OF THE LOOM TO THEREBY PROVIDE EQUAL TENSION ON THE YARN IN BOTH DIRECTIONS OF TRAVEL OF THE SHUTTLE. 